1. Field of the Invention
The present invention relates generally to artificial bone implants and specifically, to an artificial femoral implant intended to be joined to a live femur to replace a natural bone member which has been surgically resected due to trauma or disease.
2. Description of the Prior Art
The hip joint is constituted by the upper portion of the upper leg bone (femur), which terminates in an offset bony neck surmounted by a ball-headed portion which rotates within a socket (acetabulum) in the hip bone. Replacement of the hip joint by artificial implant is well known in the art, but the prior art implants have suffered from a number of disadvantages.
A conventional hip implant is performed by resecting the neck of the femur and reaming a longitudinal cavity down the femur to receive the stem of an implant. The stem of the implant is usually hammered into place and then cemented, for example, using an acrylic cement, such as methyl methacrylate. It often happens that the stem eventually works loose, either due to faulty cementing or the passage of time. This allows movement of the implant, causing bone erosion. Bone erosion can lead to tissue reactions, which themselves can lead to further bone destruction. The joint itself can then become out of alignment and/or damaged beyond repair. The presence of cement along the entire stem cavity makes removal of the implant for replacement purposes extremely difficult.